That was five years ago, they've experienced explosive growth since then which changes the equation. Because they were profitable then doesn't mean that you can simply linearly grow that as the amount of content being served grows. Particularly when you rely on ad revenue which has been on a downward trend over the last few years.

Point being: unless you have been directly involved in the decisions accusing them of either malevolence or greed is a pretty tough accusation to make. Sometimes (usually) it's cold hard business realities that drive people to adopting these sorts of monetization strategies.

So now the cycle will repeat. Someone will start a host that simply serves images. People will use it. They'll add some ads, people won't care much. They'll start serving more aggressive ads and someone will start another host... over and over again.